The effects of N-methyl-D-aspartate antagonists on the development of vestibular compensation in the guinea pig.

In order to investigate the possible role of the N-methyl-D-aspartate (NMDA) receptor in the development of the behavioural recovery which occurs following unilateral labyrinthectomy (vestibular compensation) in the guinea pig, we administered systemically the specific NMDA receptor/channel antagonists MK801 and CPP (3-((+/-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid) during the compensation process. MK801 disrupted the development of ocular motor compensation when administered at 18-22 h post-op (1.0 mg/kg i.p.). CPP had a smaller but still significant disruptive effect when injected at this time (1.0 or 5.0 mg/kg i.p.). We conclude that NMDA receptors may contribute to the development of ocular motor compensation in the guinea pig.